Switch



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Patented June 9, 1042 SWITCH Clarence E. Gary, Forest WestinghouseElectric '6 East Pittsburgh, Pa.. a corporation of F y, Pelinsy Hills,Pa., llligno i Manufacturing m Application September 21, 1938, SerialNo. 230.987

BOIahns.

This invention relates to switches.

Among the objects oi my invention is the provision or a switch oi simpleconstruction, which shall be easy economical to manuiacture; and toprovide a novel type of spring biasing action to maintain the switch inopen or in closed position.

A further object of my invention is to provide a transfer switch forcontrolling either of two circuits that shall have a simple constructionin which the switch shall be positively biased to its open neutralposition and positively biased to either of its closed positions.

In a switch of one form embodying my invention, two stationary contactsare provided to be bridged by a movable bridging contact. The bridgingcontact is mounted upon a rotatable post, and it is biased either to theopen position or to the closed position by the action of an externalpressure spring that presses radially inwardly against a rectangularelement that is transverse position. In the neutral position, the springengages the shorter surfaces of the rectangular section, and thepressure forces are opposed and symmetrically in alignment relative tothe plane of the center line of the post. When the Post is turned tomove the trailing comer edges of the rectangle beyond the center lineplane. The spring then presses against both trailing comers of therectangle in such manner as to establish a force couple that biases thebridging member into positive engagement with the stationary contacts.

position;

Fig. 5 is a side view oi the rectangle and spring to Fig. 4 showing theof Fig. 4;

Fig. 6 is a view similar rectangle and spring in operated position;

Fig. 7 is a side view of the elements of Fig. 8; and

2, of the force to assemble, and which shall be Fig. 8 is a schematicview illustrating the manner in which the bridging contact engages oneset of stationary contacts.

As shown in the drawing. the switch i consists of a main molded base 2on which are supported one pair of contacts 3 and In for one circuit,and

circuit. A bridging mlete the circuit between either set oi con- Inorder to operate the bridging contact I, a stem or post I is provided,the upper end of which is threaded and fitted into a metallic insert 1in a head screw 8 that fits into a recess in the upper end of anoperating and rotating button II. The rotating button iii is providedwith an operating portion II, and an apron II that ilts over aprojection ll of the body 2. ating button it is also provided with adepending e rtension it having a central opening or nona biasing springembodies a central portion II or annular shape central annular sectionII, so that the entire spring unit is or substantially U-shape whenviewed from the side. The two side fingers 23 and 24 are slightlyre-entrant and the entire unit is made of highly resilient spring steelso that the fingers may exert a substantial pressure against an elementoi'appropriate size between them.

In order to cooperate with the spring 20, a rectangular enlargement 15is provided as an integral part on the operating post I, to at betweenthe two flngers 23 and 24 of the spring 20.

The rectangular element 25 is normally arranged with its longerdimension in line with the pressure'iingers 22 and 24 (Fig. 4), and ismounted symmetrically with the axis of the post 8, so that normally thepressures from the fiat spring fingers 22 and 24 will oppose each otheras distributed forces against the end surfaces of the rectangularelement parallel to the longitudinal axis of the rectangular section 25.'The fiat spring fingers thus impress their pressure biasing forcesagainst areas of the element 25 to hold the bridging contact in itsneutral position against casual displacement when the bridging contactis in such neutralposition.

when the rectangular element 25 is rotated through the angle necessaryelement against the stationary contacts, the spring fingers 23 and 24will momentarily be separated an additional amount necessary to permitthe diagonal of the rectangular element to move itself between the twospring fingers 23 and 24, and the rectangular element will then continueto move past such position until it occupies the position shown in Fig.6, where the spring fingers are closer together. The diagonal of therectangular element is then overcenter and out of alignment with thecenter line through the springs, and the trailing corner edges 25a and25b of the rectangular element are on opposite sides of the center linethrough the springs, and are engaged by the respective spring fingers 23and 24 with line contact, at which the pressure force of the springfingers are concentrated.

The two springs 23and 24 where they engage the trailing corner edges 25aand 26b of the rectangular element, now impose a couple of concentratedforces tending to turn the rectangular element in the same direction inwhich it has been moved from its neutral position, and thus impress abiasing force to maintain the bridging contact 5 in positive engagementwith the pair of stationary contact members 3 and 3a, or 4 and 4a,depending upon which direction the bridging contact has been moved.Since the arrangement is symmetrical, the same condition holds whetherthe rectangular control element 25 is rotated in one direction or theother, from its neutral position. Rotation of bridging contact member 5relative its supporting bracket i5 is obviously limited in extent by theadjacent arcuate wall of base member 2 (Fig. 3).

Figs. 6 and '7 illustrate, further, how the rectangular element 25 isengaged by the spring fingers 23 and 24, when'the rectangular element isrotated with the operating shaft or post to move the bridging element 5to engage either pair of the stationary contact members;

. In Fig. 8, I have illustrated in simple form the manner in which thebridging contact 5 engages one pair of stationary contacts 4 and 4a;tocomplete the circuit between them.

In order to retain thebiaslng spring 20 in position where it willfunction, the molded base 2 is provided with two side slots 30 and 3|within which the outer .curved portion of the spring fingers 23 and 24will fit, and loosely position themselves, to prevent rotation of thespring as a unit in response to the oscillating movements of therectangular element 25 by the control shaft 6.

' When the unit is assembled, the spring is merely dropped into itsposition, and the post is extended through the opening 22 in the springto a position where the outer end of the post may be locked by the headnut 8. Thereafter, when the button It is rotated to oscillate the post 6and the pivoted bridging contact 5, the spring 20 will remain inrelatively fixed position against rotation, while to move the bridgingthe fingers 22 and 24 will be free to move in response to the minimum ormaximum space required between them according to the position of therectangular element 25.

The base 2 is provided with two bolt holes I4 and 25 in the-side wallsto permit the base to be secured to a suitable base. Access to the boltholes is available through channeled slots 36 and 31 that are depressedsufliciently below the top of the base to remove the hazard of shortcircuiting between any of the contacts and the fastening bolts.

By means of the simple rectangular element on the operating post, incooperation with the biasing spring, a positive pressure may bemaintained between the bridging contact and the stationary contacts. Theconstruction is simple and economical and serves as an effective togglein neutral position, as well as in either operating position.

My invention is not limited to any specific details that are illustratedsince these may be variously modified without departing from the spiritand scope of the invention as set forth in the appended claims.

I claim as my invention:

1. A switch comprising a stationary contact, a movable contact, arotatable member supporting the movable contact and movable therewiththrough a predetermined angle to engage the stationary contact, arectangular element mounted on and transversely of the rotatableelement, a pair of leaf springs rotatably mounted on said member anddisposed to engage and press against opposite surfaces of therectangular element in its position corresponding to the normaldisengaged position of the rectangular element, and means for holdingthe leaf springs against rotary motion in response to movement of therectangular element.

2. A switch comprising stationary contact members, a bridging contactmember, a rotatable shaft to oscillate the bridging contact intoengagement with the stationary contacts, an element on the shaftpresenting a flat pressure surface, and pressure means presenting apressure area against the pressure surface, said means including anannular ringfreely encircling the shaft and resilient fingers extendingoutwardly from the ring and extending radially inward to engage theelement on the shaft on opposite surfaces thereof and means forrestraining said last-mentioned meansagainst movement upon rotation ofsaid shaft.

3. A switch comprising a base having a pair of stationary contactssecured thereon, a movable contact to engage the stationary contacts, arotary shaft to operate the movable contact, and means loosely supportedby the shaft and engageable with cam surfaces on said shaft to bias theshaft against movement from neutral position, and to bias the shaft tocontact engaging position after a predetermined movement from neutralposition and means for restraining said last-mentioned means againstmovement with said shaft,

4. A switch comprising a base having a pair of stationary contactssecured thereon, a movable contact to engage the stationary contacts,-

for restraining rotation of said shaft.

5. A switch comprising a base having a pair of ceases in the base toenjoy free adjustability while being restrained against rotation.

6. A switch comprising a base having a pair of stationary contactssecured thereon, a movable contact to engage the stationary contacts,

7. A switch comprising two stationery spaced pairs of spaced contacts, abridging contact, a rotatable member pivotally supporting thebridgelement having adjacent angularly related surfaces mounted on andtransversely of the rotatable element, a leaf spring disposed to engageand press against one surface of said element in CLARENCE E. GARY.

